1. Field of the Invention
The technical sector of the present invention is that of devices for illuminating the road and/or for signaling and/or for illuminating the interior of the passenger compartment of a motor vehicle.
2. Description of the Related Art
In the field of automobiles, it is known to install in a vehicle a central diagnostic tool capable of diagnosing a malfunction of one or more electrical units of the vehicle in order to manage the electrical system of the vehicle. This tool is, for example, capable of detecting a drop in intensity on the electrical supply line of an electrical unit.
Furthermore, it is also known to use a command module in order to control one or more electrical units of the vehicle. In general, this command module is in particular capable of turning off the electrical supply of an electrical unit which it controls when it observes a malfunction of this unit. This turning off thus forces a drop in current on the electrical supply line so as to inform the central diagnostic tool of the malfunction.
However, in the case in which the command module controls a plurality of electrical units, it is possible to find a current line connected to the supply line of one of these units which passes through the command module in order to arrive at another of these units, or which arrives at the command module itself.
Thus, when the command module observes a malfunction of one of the electrical units, despite the supply of this unit being turned off, a residual current remains flowing on the aforementioned current line to the other unit, or to the command module itself. In this case, the central diagnostic tool is incapable of diagnosing the malfunction of the electrical unit and therefore of managing the system correctly.
One solution for overcoming this problem is to open this current line when a malfunction is observed.
However, this solution has the drawback in certain cases of interrupting the supply of the command module when it is flowing on this current line. This interruption causes closure of the current line, which will thus again supply the command module, the latter again detecting the malfunction and consequently opening the current line again. The system will thus enter an infinite loop of opening and closing the current line, which interferes considerably with its electrical management.